From 2a6009e8f24be3909239a5ab6e6d6fb53d0c5845 Mon Sep 17 00:00:00 2001
From: Matthias Schiffer <matthias@gamezock.de>
Date: Thu, 24 Dec 2009 03:24:53 +0100
Subject: Working shadow volumes! :-D

---
 src/Game.cpp   | 34 +++----------------------------
 src/Game.h     |  1 +
 src/Renderer.h | 63 +++++++++++++++++++++++++++++++++++++++++++++-------------
 3 files changed, 53 insertions(+), 45 deletions(-)

diff --git a/src/Game.cpp b/src/Game.cpp
index 1b23222..d265e83 100644
--- a/src/Game.cpp
+++ b/src/Game.cpp
@@ -55,6 +55,8 @@ Game::Game() : playerPos(vmml::vec3f::ZERO), playerRotY(vmml::mat4f::IDENTITY),
   glEnable(GL_CULL_FACE);
   glFrontFace(GL_CCW);
 
+  glEnable(GL_STENCIL_TEST);
+
   loadLevel("level.xml");
   triangles.insert(triangles.end(), level->getRooms().front().walls.begin(), level->getRooms().front().walls.end());
   std::sort(triangles.begin(), triangles.end(), Renderer::TextureSorter());
@@ -137,7 +139,7 @@ void Game::render() {
     light.z() = -8.0;
   }
 
-  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
+  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
   vmml::mat4f transform(playerRotY), inverse;
   transform.rotate_x(playerRotX);
@@ -147,36 +149,6 @@ void Game::render() {
   glLoadMatrixf(inverse.array);
 
   renderer.render(triangles, light);
-
-  Shader::disable();
-  glDepthMask(GL_FALSE);
-  glBlendFunc(GL_ONE, GL_ONE);
-  glBlendEquation(GL_FUNC_ADD);
-  glDepthFunc(GL_GREATER);
-  glColor3f(0.05, 0.05, 0.05);
-  glFrontFace(GL_CCW);
-
-  glBegin(GL_TRIANGLES);
-  for(std::vector<BSPTree::TriangleRecord>::iterator t = triangles.begin(); t != triangles.end(); ++t) {
-    ShadowVolume v(t->triangle, light);
-    v.render();
-  }
-  glEnd();
-
-  glFrontFace(GL_CW);
-  glBlendEquation(GL_FUNC_REVERSE_SUBTRACT);
-
-  glBegin(GL_TRIANGLES);
-  for(std::vector<BSPTree::TriangleRecord>::iterator t = triangles.begin(); t != triangles.end(); ++t) {
-    ShadowVolume v(t->triangle, light);
-    v.render();
-  }
-  glEnd();
-
-  glFrontFace(GL_CCW);
-  glDepthMask(GL_TRUE);
-  glDepthFunc(GL_LEQUAL);
-  glBlendEquation(GL_FUNC_ADD);
 }
 
 }
diff --git a/src/Game.h b/src/Game.h
index 7f936b4..cb90c42 100644
--- a/src/Game.h
+++ b/src/Game.h
@@ -21,6 +21,7 @@
 #define ZOOM_GAME_H_
 
 #include "Renderer.h"
+
 #include <boost/shared_ptr.hpp>
 #include <string>
 
diff --git a/src/Renderer.h b/src/Renderer.h
index eed65bb..8c531a5 100644
--- a/src/Renderer.h
+++ b/src/Renderer.h
@@ -23,6 +23,7 @@
 #include "gl.h"
 #include "BSPTree.h"
 #include "Shader.h"
+#include "ShadowVolume.h"
 #include <limits>
 
 
@@ -36,38 +37,72 @@ class Renderer {
 
     template <typename T>
     void render(const T &triangles, const vmml::vec3f &lightPos) {
+      if(triangles.empty())
+        return;
+
+      // Create shadow volumes
+      std::vector<ShadowVolume> shadowVolumes;
+      for(typename T::const_iterator t = triangles.begin(); t != triangles.end(); ++t) {
+        shadowVolumes.push_back(ShadowVolume(t->triangle, lightPos));
+      }
+
+
       glLightfv(GL_LIGHT0, GL_POSITION, vmml::vec4f(lightPos, 1).array);
 
+      // Render with ambient light
       Shader::enable(ambientShader);
       glBlendFunc(GL_ONE, GL_ZERO);
       glDepthFunc(GL_LEQUAL);
-      //glStencilFunc(GL_ALWAYS, 0, std::numeric_limits<GLuint>::max());
-      //glStencilOp(GL_KEEP, GL_INCR, GL_KEEP);
+      glStencilFunc(GL_ALWAYS, 0, std::numeric_limits<GLuint>::max());
+      glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
 
-      typename T::const_iterator t = triangles.begin();
-      if(t == triangles.end())
-        return;
-
-      useTexture(t->triangle.getTexture());
+      useTexture(triangles.front().triangle.getTexture());
 
       glBegin(GL_TRIANGLES);
-      for(; t != triangles.end(); ++t) {
+      for(typename T::const_iterator t = triangles.begin(); t != triangles.end(); ++t) {
         renderTriangle(t->triangle);
       }
       glEnd();
 
+      // Render shadow volumes
+      glClear(GL_STENCIL_BUFFER_BIT);
+      glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
+      glDepthMask(GL_FALSE);
+      Shader::disable();
+
+      glFrontFace(GL_CCW);
+      glStencilOp(GL_KEEP, GL_INCR_WRAP, GL_KEEP);
+
+      glBegin(GL_TRIANGLES);
+      for(std::vector<ShadowVolume>::iterator v = shadowVolumes.begin(); v != shadowVolumes.end(); ++v) {
+        v->render();
+      }
+      glEnd();
+
+      glFrontFace(GL_CW);
+      glStencilOp(GL_KEEP, GL_DECR_WRAP, GL_KEEP);
+
+      glBegin(GL_TRIANGLES);
+      for(std::vector<ShadowVolume>::iterator v = shadowVolumes.begin(); v != shadowVolumes.end(); ++v) {
+        v->render();
+      }
+      glEnd();
+
+      glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
+      glDepthMask(GL_TRUE);
+      glFrontFace(GL_CCW);
+
+      // Render with point light
       Shader::enable(lightShader);
       glBlendFunc(GL_ONE, GL_ONE);
       glDepthFunc(GL_EQUAL);
-      //glStencilFunc(GL_EQUAL, 0, std::numeric_limits<GLuint>::max());
-      //glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
-
-      t = triangles.begin();
+      glStencilFunc(GL_EQUAL, 0, std::numeric_limits<GLuint>::max());
+      glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
 
-      useTexture(t->triangle.getTexture());
+      useTexture(triangles.front().triangle.getTexture());
 
       glBegin(GL_TRIANGLES);
-      for(; t != triangles.end(); ++t) {
+      for(typename T::const_iterator t = triangles.begin(); t != triangles.end(); ++t) {
         renderTriangle(t->triangle);
       }
       glEnd();
-- 
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